LED lamp circuit using switch to set color temperature

Abstract

The utility model discloses an LED lamp circuit for setting color temperature by using a switch, which is characterized in that a reference voltage circuit, a signal setting circuit and a switch state circuit are arranged, and a mechanical switch of the signal setting circuit is operated to enable the signal setting circuit to output different direct-current voltage signals; the on-off state circuit can only control the first LED circuit to emit high-color-temperature light or only control the second LED circuit to emit low-color-temperature light or control the first LED circuit and the second LED circuit to alternately emit light to form mixed light of the high-color-temperature light and the low-color-temperature light according to the direct-current voltage signal output by the signal setting circuit; the LED driving circuit has the advantages that when the first LED circuit and the second LED circuit alternately emit light, the proportion of the average current magnitude between the first LED circuit and the second LED circuit is irrelevant to the deviation between the working voltage of the first LED circuit and the working voltage of the second LED circuit, the phenomenon of current snatching is avoided, and color temperature deviation of mixed light of high-color-temperature light and low-color-temperature light can be avoided in practical application.

Description

Technical Field

[0001] The utility model relates to an LED lamp circuit, in particular to an LED lamp circuit which utilizes a switch to set the color temperature. Background Art

[0002] like Figure 1 As shown, the existing LED lamp circuit using a switch to set the color temperature generally includes a constant current power supply circuit, two LED circuits and a switch setting circuit. The constant current power supply circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal. The constant current power supply circuit is used to convert the AC voltage of the mains connected between the first input terminal and the second input terminal into a DC current and output it between the positive output terminal and the negative output terminal. The two LED circuits are respectively referred to as the first LED circuit and the second LED circuit. The first LED circuit has a positive pole and a negative pole. When a DC current is connected between the positive pole and the negative pole, it emits a high color temperature light. The second LED circuit has a positive pole and a negative pole. When a DC current is connected between the positive pole and the negative pole, it emits a low color temperature light. The switch setting circuit has a first connection terminal, a second connection terminal and a common terminal, and the first connection terminal and the second connection terminal are cut off, and the first connection terminal and the second connection terminal can both be connected to their common terminal. The switch setting circuit has three states, respectively referred to as the first state, the second state and the third state. In the first state, the first connection terminal and the common terminal are connected, and the second connection terminal and the common terminal are cut off; in the second state, the first connection terminal and the common terminal are connected, and the second connection terminal and the common terminal are also connected; in the third state, the first connection terminal and the common terminal are cut off, and the second connection terminal and the common terminal are cut off. The three states of the switch setting circuit can be set by operating the mechanical switch inside the switch setting circuit. The positive pole of the first LED circuit and the positive pole of the second LED circuit are both connected to the positive output terminal of the constant current power supply circuit, the negative pole of the first LED circuit is connected to the first connection terminal of the switch setting circuit, the negative pole of the second LED circuit is connected to the second connection terminal of the switch setting circuit, and the common terminal of the switch setting circuit is connected to the negative output terminal of the constant current power supply circuit.

[0003] In the above-mentioned LED lamp circuit using a switch to set the color temperature, when the AC voltage of the mains is connected between the first input terminal and the second input terminal of the constant current power supply circuit, a DC current is output between the positive output terminal and the negative output terminal of the constant current power supply circuit. If the switch setting circuit is in the first state, the DC current output between the positive output terminal and the negative output terminal of the constant current power supply circuit only passes through the first LED circuit, the first LED circuit emits light, and the LED lamp circuit emits high color temperature light at this time; if the switch setting circuit is in the second state, the DC current output between the positive output terminal and the negative output terminal of the constant current power supply circuit passes through the first LED circuit and the second LED circuit at the same time, the first LED circuit and the second LED circuit both emit light, and the light emitted by the LED lamp circuit is a mixed light of the high color temperature light emitted by the first LED circuit and the low color temperature light emitted by the second LED circuit, and the color temperature of the mixed light corresponds to the ratio between the luminous intensity of the first LED circuit and the luminous intensity of the second LED circuit; if the switch setting circuit is in the third state, the DC current output between the positive output terminal and the negative output terminal of the constant current power supply circuit only passes through the second LED circuit, the second LED circuit emits light, and the light emitted by the LED lamp circuit is low color temperature light emitted by the second LED circuit.

[0004] In actual applications of the above-mentioned LED lamp circuit that uses a switch to set the color temperature, when the switch setting circuit is in the second state, the color temperature of the mixed light it emits corresponds to the ratio between the luminous intensity of the first LED circuit and the luminous intensity of the second LED circuit, and there is inevitably a deviation in the operating voltages of the two LED circuits. The LED circuit with a lower operating voltage will flow a larger current than the LED circuit with a higher operating voltage, resulting in a "current grabbing" phenomenon. At this time, the ratio between the luminous intensity of the first LED circuit and the luminous intensity of the second LED circuit will change, resulting in an obvious color temperature shift. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide an LED lamp circuit for setting the color temperature by using a switch, which can reduce the color temperature deviation of mixed light of high color temperature light and low color temperature light in practical applications.

[0006] The technical solution adopted by the utility model to solve the above technical problems is: an LED lamp circuit using a switch to set the color temperature, including a constant current power supply circuit and two LED circuits, the constant current power supply circuit is used to convert the AC voltage of the mains into a DC current output and generate a DC voltage output, the two LED circuits are respectively called a first LED circuit and a second LED circuit, the first LED circuit can emit high color temperature light when connected to the DC current output by the constant current power supply circuit, the second LED circuit can emit low color temperature light when connected to the DC current output by the constant current power supply circuit, the LED lamp circuit using a switch to set the color temperature also includes a reference voltage circuit, a signal setting circuit and a switch state circuit, wherein the reference voltage circuit is used to convert the DC voltage output by the constant current power supply circuit into a constant DC voltage output to the signal setting circuit, wherein the signal setting circuit includes a mechanical switch, wherein the mechanical switch is used to set the output state of the signal setting circuit so that the signal setting circuit can output different DC voltage signals to the switch state circuit under different output states, and the switch state circuit is used to enable only one of the two LED circuits to be connected to the DC current output by the constant current power supply circuit, or to enable the two LED circuits to be alternately connected to the DC current output by the constant current power supply circuit, according to the DC voltage signal output by the signal setting circuit.

[0007] The constant current power supply circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal, and the first input terminal and the second input terminal are used to connect to the AC voltage of the mains, and the positive output terminal and the negative output terminal are used to output DC current and DC voltage. The first LED circuit has a positive electrode and a negative electrode, and emits high color temperature light after the DC current output by the constant current power supply circuit is connected between the positive electrode and the negative electrode. The second LED circuit has a positive electrode and a negative electrode, and emits low color temperature light after the DC current output by the constant current power supply circuit is connected between the positive electrode and the negative electrode. The reference voltage circuit has an input terminal, an output terminal and a negative electrode. , the signal setting circuit has an input terminal, an output terminal and a negative electrode; the switch state circuit has a first positive electrode, a second positive electrode, a negative electrode, an input terminal, a first output terminal and a second output terminal, the switch state circuit is provided with a first voltage threshold and a second voltage threshold, and the first voltage threshold is greater than the second voltage threshold, when the DC voltage signal connected to its input terminal is greater than or equal to the first voltage threshold, the first output terminal and the negative electrode are connected, and the second output terminal and the negative electrode are cut off, when the DC voltage signal connected to its input terminal is less than or equal to the second voltage threshold, the first output terminal and the negative electrode are cut off, and the second The output terminal and the cathode are connected, and when the DC voltage signal connected to the input terminal is less than the first voltage threshold and greater than the second voltage threshold, the first output terminal and the second output terminal are alternately connected to the cathode, and the frequency of the change is greater than 100HZ. The ratio of the conduction time between the first output terminal and the cathode of the switch state circuit and the conduction time between the second output terminal and the cathode corresponds to the magnitude of the DC voltage signal connected to the input terminal; the anode of the first LED circuit, the anode of the second LED circuit, the first anode of the switch state circuit, the input terminal of the reference voltage circuit and the constant The positive output end of the current power supply circuit is connected, the negative pole of the first LED circuit is connected to the first output end of the switch state circuit, the negative pole of the second LED circuit is connected to the second output end of the switch state circuit, the input end of the switch state circuit is connected to the output end of the signal setting circuit, the second positive pole of the switch state circuit, the input end of the signal setting circuit are connected to the output end of the reference voltage circuit, the negative pole of the switch state circuit, the negative pole of the signal setting circuit, the negative pole of the reference voltage circuit and the negative output end of the constant current circuit are connected.

[0008] The reference voltage circuit includes a first integrated circuit of model TL431, a first resistor, a second resistor and a third resistor, one end of the first resistor is the input end of the reference voltage circuit, the other end of the first resistor and one end of the second resistor are connected to the K pin of the first integrated circuit, and their connection ends are the output end of the reference voltage circuit, the other end of the second resistor and one end of the third resistor are connected to the R pin of the first integrated circuit, the other end of the third resistor is connected to the A pin of the first integrated circuit, and its connection end is the negative electrode of the reference voltage circuit.

[0009] The signal setting circuit also includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a first capacitor. The mechanical switch is a five-choice toggle switch. The five-choice toggle switch has a common pin and five connecting pins. By toggling the five-choice toggle switch, its five connecting pins can be connected to its common pin respectively. Its five connecting pins are respectively called pin 1, pin 2, pin 3, pin 4 and pin 5. One end of the fourth resistor is the input end of the signal setting circuit. The other end of the fourth resistor, one end of the fifth resistor, one end of the sixth resistor, one end of the seventh resistor, one end of the eighth resistor, and the One end of the ninth resistor is connected to one end of the first capacitor, and its connection end is the output end of the signal setting circuit, the other end of the fifth resistor is connected to the first pin of the five-choice toggle switch, the other end of the sixth resistor is connected to the second pin of the five-choice toggle switch, the other end of the seventh resistor is connected to the third pin of the five-choice toggle switch, the other end of the eighth resistor is connected to the fourth pin of the five-choice toggle switch, the other end of the ninth resistor is connected to the fifth pin of the five-choice toggle switch, the common pin of the five-choice fluctuation switch is connected to the other end of the first capacitor, and its connection end is the negative pole of the signal setting circuit.

[0010] The switch state circuit includes a second integrated circuit of model BP5936D, a tenth resistor and a second capacitor. The VH pin of the second integrated circuit is the first positive electrode of the switch state circuit. The VCC pin of the second integrated circuit is connected to one end of the second capacitor, and its connection end is the second positive electrode of the switch state circuit. The D1 pin of the second integrated circuit is the first output end of the switch state circuit. The D2 pin of the second integrated circuit is the second output end of the switch state circuit. The PWM pin of the second integrated circuit is the input end of the switch state circuit. One end of the tenth resistor is connected to the Rdelay pin of the second integrated circuit. The other end of the tenth resistor, the other end of the second capacitor, the VS pin of the second integrated circuit and the GND pin are connected, and their connection ends are the negative electrode of the switch state circuit.

[0011] Compared with the prior art, the utility model has the advantages that by setting a reference voltage circuit, a signal setting circuit and a switch state circuit, the mechanical switch of the signal setting circuit can be operated to make the signal setting circuit output different DC voltage signals, and the switch state circuit can present different states according to the DC voltage signal output by the signal setting circuit, either only controlling the first LED circuit to emit high color temperature light, or only controlling the second LED circuit to emit low color temperature light, or controlling the first LED circuit and the second LED circuit to alternately emit light to form a mixed light of high color temperature light and low color temperature light. When the first LED circuit and the second LED circuit alternately emit light, the ratio of the average current size between the first LED circuit and the second LED circuit only corresponds to the size of the DC voltage signal output by the signal setting circuit, and has nothing to do with the deviation between the working voltages of the first LED circuit and the second LED circuit, and the "current grabbing" phenomenon will not occur. Therefore, in practical applications, the color temperature deviation of the mixed light of high color temperature light and low color temperature light can be reduced, and when the first LED circuit and the second LED circuit alternately emit light, the time for the first LED circuit and the second LED circuit to alternately emit light can be different by setting different sizes of DC voltage signals, so that the first LED circuit and the second LED circuit also present a variety of color temperatures when they alternately emit light. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The structure diagram of the existing LED lamp circuit for setting the color temperature by using a switch;

[0013] Figure 2 This is a structural diagram of an LED lamp circuit for setting color temperature using a switch according to the present invention;

[0014] Figure 3 This is a partial circuit diagram of an LED lamp circuit that uses a switch to set the color temperature of the present invention. DETAILED DESCRIPTION

[0015] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0016] Embodiment 1: Figure 2 As shown, an LED lamp circuit for setting color temperature by using a switch includes a constant current power supply circuit and two LED circuits. The constant current power supply circuit is used to convert the AC voltage of the mains into a DC current output and generate a DC voltage output. The two LED circuits are respectively referred to as a first LED circuit and a second LED circuit. The first LED circuit can emit high color temperature light when connected to the DC current output by the constant current power supply circuit, and the second LED circuit can emit low color temperature light when connected to the DC current output by the constant current power supply circuit. The LED lamp circuit for setting color temperature by using a switch also includes a reference voltage circuit, a signal setting circuit and a switch state circuit. The reference voltage circuit is used to convert the DC voltage output by the constant current power supply circuit into a constant DC voltage output to the signal setting circuit. The signal setting circuit includes a mechanical switch. The mechanical switch is used to set the output state of the signal setting circuit so that the signal setting circuit can output different DC voltage signals to the switch state circuit under different output states. The switch state circuit is used to connect only one of the two LED circuits to the DC current output by the constant current power supply circuit according to the DC voltage signal output by the signal setting circuit, or to connect the two LED circuits alternately to the DC current output by the constant current power supply circuit.

[0017] In this embodiment, by setting a reference voltage circuit, a signal setting circuit and a switch state circuit, operating the mechanical switch of the signal setting circuit can make the signal setting circuit output different DC voltage signals, and the switch state circuit can present different states according to the DC voltage signal output by the signal setting circuit, either only controlling the first LED circuit to emit high color temperature light, or only controlling the second LED circuit to emit low color temperature light, or controlling the first LED circuit and the second LED circuit to alternately emit light to form a mixed light of high color temperature light and low color temperature light. When the first LED circuit and the second LED circuit alternately emit light, the ratio of the average current size between the first LED circuit and the second LED circuit only corresponds to the size of the DC voltage signal output by the signal setting circuit, and has nothing to do with the deviation between the working voltages of the first LED circuit and the second LED circuit, and the "current grabbing" phenomenon will not occur. Therefore, in practical applications, the color temperature deviation of the mixed light of high color temperature light and low color temperature light can be reduced, and when the first LED circuit and the second LED circuit alternately emit light, the time for the first LED circuit and the second LED circuit to alternately emit light can be different by setting different sizes of DC voltage signals, so that the first LED circuit and the second LED circuit also present a variety of color temperatures when they alternately emit light.

[0018] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, the constant current power supply circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal, and its first input terminal and the second input terminal are used to connect to the AC voltage of the mains, and its positive output terminal and the negative output terminal are used to output DC current and DC voltage. The first LED circuit has a positive electrode and a negative electrode, and after the DC current output by the constant current power supply circuit is connected between its positive and negative electrodes, a high color temperature light is emitted. The second LED circuit has a positive electrode and a negative electrode, and after the DC current output by the constant current power supply circuit is connected between its positive and negative electrodes, a low color temperature light is emitted. The reference voltage circuit has The switch state circuit has a first positive pole, a second positive pole, a negative pole, an input end, a first output end, and a second output end. The switch state circuit is provided with a first voltage threshold and a second voltage threshold, and the first voltage threshold is greater than the second voltage threshold. When the DC voltage signal connected to the input end is greater than or equal to the first voltage threshold, the first output end and the negative pole are connected, and the second output end and the negative pole are cut off. When the DC voltage signal connected to the input end is less than or equal to the second voltage threshold, the first output end and the negative pole are cut off, and the second output end and the negative pole are cut off. The output terminal and the cathode are connected, and when the DC voltage signal connected to the input terminal is less than the first voltage threshold and greater than the second voltage threshold, the first output terminal and the second output terminal are alternately connected to the cathode, and the frequency of the change is greater than 100HZ, that is, when the first output terminal and the cathode are connected, the second output terminal and the cathode are cut off, and when the first output terminal and the cathode are cut off, the second output terminal and the cathode are connected, and the ratio of the conduction time between the first output terminal and the cathode of the switch state circuit and the conduction time between the second output terminal and the cathode corresponds to the size of the DC voltage signal connected to the input terminal; the first LED circuit The positive electrode of the first LED circuit, the positive electrode of the second LED circuit, the first positive electrode of the switch state circuit, the input end of the reference voltage circuit and the positive output end of the constant current power supply circuit are connected, the negative electrode of the first LED circuit and the first output end of the switch state circuit are connected, the negative electrode of the second LED circuit and the second output end of the switch state circuit are connected, the input end of the switch state circuit and the output end of the signal setting circuit are connected, the second positive electrode of the switch state circuit, the input end of the signal setting circuit and the output end of the reference voltage circuit are connected, and the negative electrode of the switch state circuit, the negative electrode of the signal setting circuit, the negative electrode of the reference voltage circuit and the negative output end of the constant current circuit are connected.

[0019] In this embodiment, when the AC voltage of the mains is connected between the first input terminal and the second input terminal of the constant current power supply circuit, a DC current is output between the positive output terminal and the negative output terminal thereof, and a DC voltage output is generated at the same time. The reference voltage circuit converts the DC voltage output between the positive output terminal and the negative output terminal of the constant current power supply circuit, and outputs a stable DC voltage at its output terminal. The signal setting circuit outputs a DC voltage signal of corresponding magnitude at its output terminal according to the output state set by its mechanical switch. The input terminal of the switch state circuit is connected to the DC voltage signal output by the output terminal of the signal setting circuit. The conduction state between the first output terminal and the second output terminal of the switch state circuit and its negative electrode corresponds to the magnitude of the DC voltage signal connected to its input terminal. When the DC voltage signal connected to its input terminal is greater than or equal to the first voltage threshold, the first LED circuit emits light, and at this time the LED lamp circuit emits high color temperature light. When the DC voltage signal connected to its input terminal is less than or equal to the second voltage threshold, the second LED circuit emits light, and at this time the LED lamp circuit emits low color temperature light. When the DC voltage signal connected to its input terminal is less than or equal to the second voltage threshold, the second LED circuit emits light, and at this time the LED lamp circuit emits low color temperature light. When the connected DC voltage signal is less than the first voltage threshold and greater than the second voltage threshold, the first output terminal and the cathode and the second output terminal and the cathode are alternately turned on. When the first output terminal and the cathode are turned on, the first LED circuit emits light, and when the second output terminal and the cathode are turned on, the second LED circuit emits light. At this time, the LED lamp circuit emits a mixture of high color temperature light and low color temperature light. Because the ratio between the average current driving the first LED circuit to emit light and the average current driving the second LED circuit to emit light is the same as the ratio between the conduction time between the first output terminal and the cathode of the switch state circuit and the conduction time between the second output terminal and the cathode, the light intensity ratio between the first LED circuit and the second LED circuit corresponds to the ratio of the conduction time between the first output terminal and the cathode of the switch state circuit to the conduction time between the second output terminal and the cathode, and the color temperature of the mixed light corresponds to the ratio of the conduction time between the first output terminal and the cathode of the switch state circuit to the conduction time between the second output terminal and the cathode.

[0020] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 3 As shown, the reference voltage circuit includes a first integrated circuit U1 of model TL431, a first resistor R1, a second resistor R2 and a third resistor R3, one end of the first resistor R1 is the input end of the reference voltage circuit, the other end of the first resistor R1 and one end of the second resistor R2 are connected to the K pin of the first integrated circuit U1, and the connection end thereof is the output end of the reference voltage circuit, the other end of the second resistor R2 and one end of the third resistor R3 are connected to the R pin of the first integrated circuit U1, the other end of the third resistor R3 is connected to the A pin of the first integrated circuit U1, and the connection end thereof is the negative electrode of the reference voltage circuit.

[0021] Embodiment 4: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 3 As shown, the signal setting circuit also includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a first capacitor C1, the mechanical switch is a five-choice toggle switch, the five-choice toggle switch has a common pin and five connecting pins, and the five connecting pins can be connected to the common pin by toggling the five-choice toggle switch, and the five connecting pins are respectively referred to as the first pin, the second pin, the third pin, the fourth pin and the fifth pin, one end of the fourth resistor R4 is the input end of the signal setting circuit, and the other end of the fourth resistor R4, one end of the fifth resistor R5, one end of the sixth resistor R6, and one end of the seventh resistor R7 are connected to the common pin. , one end of the eighth resistor R8, one end of the ninth resistor R9 and one end of the first capacitor C1 are connected, and their connection ends are the output end of the signal setting circuit, the other end of the fifth resistor R5 is connected to the first pin of the five-choice toggle switch, the other end of the sixth resistor R6 is connected to the second pin of the five-choice toggle switch, the other end of the seventh resistor R7 is connected to the third pin of the five-choice toggle switch, the other end of the eighth resistor R8 is connected to the fourth pin of the five-choice toggle switch, the other end of the ninth resistor R9 is connected to the fifth pin of the five-choice toggle switch, the common pin of the five-choice wave switch is connected to the other end of the first capacitor C1, and their connection ends are the negative electrode of the signal setting circuit.

[0022] In this embodiment, in the signal setting circuit, by toggling the five-to-one toggle switch, one of the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the ninth resistor R9 can be connected to the circuit, thereby forming a voltage divider circuit with the fourth resistor R4, so that the output end of the signal setting circuit outputs a DC voltage signal of corresponding magnitude. Therefore, by setting the resistance values ​​of the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the ninth resistor R9, the output end of the signal setting circuit can output 5 DC voltage signals of different magnitudes, and one of the DC voltage signals is less than or equal to the second voltage threshold, one DC voltage signal is greater than or equal to the first voltage threshold, and the other three DC voltage signals are greater than the second voltage threshold and less than the first voltage threshold, thereby enabling the setting of five color temperatures.

[0023] Embodiment 4: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 3As shown, the switch state circuit includes a second integrated circuit U2 of model BP5936D, a tenth resistor R10 and a second capacitor C2, the VH pin of the second integrated circuit U2 is the first positive electrode of the switch state circuit, the VCC pin of the second integrated circuit is connected to one end of the second capacitor C2, and the connection end thereof is the second positive electrode of the switch state circuit, the D1 pin of the second integrated circuit U2 is the first output end of the switch state circuit, the D2 pin of the second integrated circuit U2 is the second output end of the switch state circuit, the PWM pin of the second integrated circuit U2 is the input end of the switch state circuit, one end of the tenth resistor R10 is connected to the Rdelay pin of the second integrated circuit U2, the other end of the tenth resistor R10, the other end of the second capacitor, the VS pin of the second integrated circuit U2 and the GND pin are connected, and the connection end thereof is the negative electrode of the switch state circuit.

Claims

1. An LED lamp circuit for setting color temperature by using a switch, comprising a constant current power supply circuit and two LED circuits, wherein the constant current power supply circuit is used to convert the AC voltage of the mains into a DC current output and generate a DC voltage output, and the two LED circuits are respectively referred to as a first LED circuit and a second LED circuit, wherein the first LED circuit can emit high color temperature light when connected to the DC current output by the constant current power supply circuit, and the second LED circuit can emit low color temperature light when connected to the DC current output by the constant current power supply circuit, characterized in that It also includes a reference voltage circuit, a signal setting circuit and a switch state circuit. The reference voltage circuit is used to convert the DC voltage output by the constant current power supply circuit into a constant DC voltage output to the signal setting circuit. The signal setting circuit includes a mechanical switch. The mechanical switch is used to set the output state of the signal setting circuit so that the signal setting circuit can output different DC voltage signals to the switch state circuit under different output states. The switch state circuit is used to connect only one of the two LED circuits to the DC current output by the constant current power supply circuit according to the DC voltage signal output by the signal setting circuit, or to connect the two LED circuits alternately to the DC current output by the constant current power supply circuit.

2. The LED lamp circuit for setting the color temperature by using a switch according to claim 1, characterized in that The constant current power supply circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal, and the first input terminal and the second input terminal are used to connect to the AC voltage of the mains, and the positive output terminal and the negative output terminal are used to output DC current and DC voltage. The first LED circuit has a positive electrode and a negative electrode, and emits high color temperature light after the DC current output by the constant current power supply circuit is connected between the positive electrode and the negative electrode. The second LED circuit has a positive electrode and a negative electrode, and emits low color temperature light after the DC current output by the constant current power supply circuit is connected between the positive electrode and the negative electrode. The reference voltage circuit has an input terminal, an output terminal and a negative electrode. , the signal setting circuit has an input terminal, an output terminal and a negative electrode; the switch state circuit has a first positive electrode, a second positive electrode, a negative electrode, an input terminal, a first output terminal and a second output terminal, the switch state circuit is provided with a first voltage threshold and a second voltage threshold, and the first voltage threshold is greater than the second voltage threshold, when the DC voltage signal connected to its input terminal is greater than or equal to the first voltage threshold, the first output terminal and the negative electrode are connected, and the second output terminal and the negative electrode are cut off, when the DC voltage signal connected to its input terminal is less than or equal to the second voltage threshold, the first output terminal and the negative electrode are cut off, and the second The output terminal and the cathode are connected, and when the DC voltage signal connected to the input terminal is less than the first voltage threshold and greater than the second voltage threshold, the first output terminal and the second output terminal are alternately connected to the cathode, and the frequency of the change is greater than 100HZ. The ratio of the conduction time between the first output terminal and the cathode of the switch state circuit and the conduction time between the second output terminal and the cathode corresponds to the magnitude of the DC voltage signal connected to the input terminal; the anode of the first LED circuit, the anode of the second LED circuit, the first anode of the switch state circuit, the input terminal of the reference voltage circuit and the constant The positive output end of the constant current power supply circuit is connected, the negative pole of the first LED circuit is connected to the first output end of the switch state circuit, the negative pole of the second LED circuit is connected to the second output end of the switch state circuit, the input end of the switch state circuit is connected to the output end of the signal setting circuit, the second positive pole of the switch state circuit, the input end of the signal setting circuit are connected to the output end of the reference voltage circuit, the negative pole of the switch state circuit, the negative pole of the signal setting circuit, the negative pole of the reference voltage circuit are connected to the negative output end of the constant current power supply circuit.

3. The LED lamp circuit for setting the color temperature by using a switch according to claim 2, characterized in that The reference voltage circuit includes a first integrated circuit of model TL431, a first resistor, a second resistor and a third resistor, one end of the first resistor is the input end of the reference voltage circuit, the other end of the first resistor and one end of the second resistor are connected to the K pin of the first integrated circuit, and their connection ends are the output end of the reference voltage circuit, the other end of the second resistor and one end of the third resistor are connected to the R pin of the first integrated circuit, the other end of the third resistor is connected to the A pin of the first integrated circuit, and its connection end is the negative electrode of the reference voltage circuit.

4. The LED lamp circuit for setting the color temperature by using a switch according to claim 2, characterized in that The signal setting circuit also includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a first capacitor. The mechanical switch is a five-choice toggle switch. The five-choice toggle switch has a common pin and five connecting pins. By toggling the five-choice toggle switch, its five connecting pins can be connected to its common pin respectively. Its five connecting pins are respectively called pin 1, pin 2, pin 3, pin 4 and pin 5. One end of the fourth resistor is the input end of the signal setting circuit. The other end of the fourth resistor, one end of the fifth resistor, one end of the sixth resistor, one end of the seventh resistor, one end of the eighth resistor, and the One end of the ninth resistor is connected to one end of the first capacitor, and its connection end is the output end of the signal setting circuit, the other end of the fifth resistor is connected to the first pin of the five-choice toggle switch, the other end of the sixth resistor is connected to the second pin of the five-choice toggle switch, the other end of the seventh resistor is connected to the third pin of the five-choice toggle switch, the other end of the eighth resistor is connected to the fourth pin of the five-choice toggle switch, the other end of the ninth resistor is connected to the fifth pin of the five-choice toggle switch, the common pin of the five-choice toggle switch is connected to the other end of the first capacitor, and its connection end is the negative pole of the signal setting circuit.

5. The LED lamp circuit for setting the color temperature by using a switch according to claim 2, characterized in that The switch state circuit includes a second integrated circuit of model BP5936D, a tenth resistor and a second capacitor. The VH pin of the second integrated circuit is the first positive electrode of the switch state circuit. The VCC pin of the second integrated circuit is connected to one end of the second capacitor, and the connection end is the second positive electrode of the switch state circuit. The D1 pin of the second integrated circuit is the first output end of the switch state circuit. The D2 pin of the second integrated circuit is the second output end of the switch state circuit. The PWM pin of the second integrated circuit is the input end of the switch state circuit. One end of the tenth resistor is connected to the Rdelay pin of the second integrated circuit. The other end of the tenth resistor, the other end of the second capacitor, the VS pin of the second integrated circuit and the GND pin are connected, and the connection end is the negative electrode of the switch state circuit.

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